This invention relates to punch machine for punching a hole out of material to be punched, such as a sheet by engaging a punch and a die with each other, and relates to punch machine equipped with a copying machine, a printer, a facsimile machine and a main body of an image forming unit of apparatus combining these machines, or a printing machine, for instance.
As shown in FIG. 13, in this kind of conventional punch machine, a pair of decentering cams 23, 23 are unitedly provided with a rotating shaft 22 rotating by a motor 21, and both ends of a punch holding member 25 having predetermined number of punches, for instance three punches 24, are supported by a pair of decentering cams 23, 23.
When the decentering cams 23, 23 are rotated, the punch 24 goes up and down by guiding by a guide hole 26. On this occasion, the punch 24 is inserted in and engaged with the die 27 so as to punch a hole out of sheet P, which is stopping material to be punched, such as paper.
The going up and down distance of the punch 24 of the conventional punch machine 20 is set rather long in comparison with thickness of a sheet. This distance is extremely shorter than the length of a sheet.
For this reason, when the punch 24 of the conventional punch machine 20 is continuously moved up and down, the punch may descend again before taking the sheet already punched out of the punch machine 20. So, there is a danger of punching the same sheet again. Therefore, the punch 24 is stopped at a waiting position away from a sheet until the sheet is taken out after punching a hole out of the sheet and a next sheet is set.
And, the punch 24 is provided with punch holding member 25, going up and down by transmitting the rotational force of the motor 21 to the decentering cams 23 through reducing gear mechanism 28 and the rotating shaft 22. Then, even if a motor 21 is stopped so as to try to stop the punch 24 at the utmost upper position, it is difficult to stop the punch 24 at the utmost upper position by inertia force, such as the motor 21 and the punch holding member 25.
Besides, when the motor 21 is rotated at high speed so as to move the punch 24 up and down at high speed in order to improve machining efficiency of punching machining, the inertia force becomes to be further bigger. Then, it is much difficult to correctly stop the punch 24 at the utmost upper position.
Furthermore, the conventional punch machine 20 has the structure that the position and the number of the punches 24 can not be changed. Then, the position and the number of the hole to be punched out of a sheet can not be changed.
The object of the present invention is to provide punch machine wherein the punches can be certainly waited at waiting positions so as not to give the punches the influence of the inertia force of the rotating driving means for moving the punch even if the punches are moved at high speed, and the position and number of holes to be punched out of a sheet can be changed.
A punch machine comprises a plurality of punches and dies for punching holes out of material. Driving means for reciprocating in first and second directions intersecting with respect to the punches by a driving force of a driving source is provided. The punch machine also has a cam mechanism for changing the reciprocating motion of the driving direction into a direction moving the punch and transmitting it to the punch; the cam mechanism is provided between each punch and the driving means.
The plurality of punches is divided into a first group and a second group. The cam mechanism is located between each punch of the first group and the driving means. The cam mechanism moves each punch by movement operation of the driving means in the first direction. The cam mechanism located between each punch of the second group and the driving means moves each punch by movement operation of the driving means in the second direction.
When the driving means is actuated, the motion of the driving means is changed into the moving direction of the punch by the cam mechanism. As a result, the punch punches a hole out of a sheet while advancing it into the die. In this case, the first group of the punch punches a hole out of the sheet and the second group of the punch punches a hole out of the sheet when the driving means is moved in the first and second directions, respectively.
Because the first group of the punch and the second group of the punch are located at positions different from each other, the positions of the holes to be punched out of the sheet by the first and second groups are also different from each other; the position of the holes to be punched out of a sheet can be changed by the movement direction of the driving means. The number of the holes to be punched out of a sheet also can be changed if the number of punches of the first group and the second group differ. Therefore, the punch machine of the present invention is a single machine that performs the functions of two machines.
The punch machine can prevent the punch from driving in the direction of the material to be punched even if the driving means overruns by the influence of inertia by driving the punch through use of the cam mechanism. The position of the punch can be easily controlled without greatly affecting the accuracy and positioning of the driving source.
Optionally, the punch machine can have a cam mechanism that has a cam slot and a cam-follower engaging with the cam slot. Energizing means, for energizing the punch in a direction approaching the material to be punched, can also be provided with the punch.
The punch machine may incorporate a cam mechanism so that each punch moves with a predetermined phase difference among the punches comprising each group.
The punch machine may also incorporate driving means having a plate member being free to reciprocate and drive by the driving source, wherein the cam slot is formed on the plate member, and the cam-follower is provided with the punch. In this structure, the cam slot can be easily formed, corresponding to each punch, and the driving mechanism can be made simple.
The punch machine may incorporate driving means having a plate member being free to reciprocate and drive by the driving source, wherein the cam follower is formed on the plate member, and the cam slot may be formed on the punch side.
The punch machine may incorporate driving means having a belt member being free to reciprocate and drive by the driving source and a plurality of cam cylinders for reciprocally rotating and driving in predetermined angular bounds by the belt member; the cam cylinders are respectively provided, corresponding to each punch, and the cam mechanism is provided between the cam cylinder and the punch. Because the flexible belt member can be used as the driving means, the freedom of the arrangement of the driving source and the punches is increased and functional design is possible.
The punch machine may incorporate cam mechanisms provided for respective punches. By providing the cam mechanism for each punch, independent motion can be added to each punch and the complex motion patterns of the punch can be actualized. Additionally, the punch machine provides for a cam mechanism to be used for two or more punches.
The structure can be made simple by using the cam mechanism. For example, the arrangement interval among the punches can be made narrower and a punch arrangement having various intervals can be obtained.
The punch machine may also incorporate driving means having a plate member comprised of a single plate member; the plate member can be free to reciprocate and drive by the driving source, and the cam mechanism can be respectively provided between the plate member and the punch. All of the punches can be reciprocated and driven through the plate member by reciprocating the plate member. Additionally, all of the punches can be driven with a single plate member, and the mechanism for driving the punches can be made simple and small.
The punch machine may provide for the cam mechanism having a cam slot, engaging with a plurality of the cam-followers. By using the cam mechanism, the structure of the cam mechanism can be made simple. Additionally, the arrangement interval among the punches can be made narrower and a punch arrangement having various intervals can be obtained.
The punch machine may have means for holding the driving means. This results in the driving means being capable of being held at a predetermined position of the reciprocating motion.
The punch machine may incorporate a different number of the punches for the first and second groups. Thus, the punching operation is possible by combining various numbers of holes.
The punch machine may also have a plurality of punches belonging to the first group, a plurality of punches belonging to the second group, and the arrangement pitch for the first and second groups being different from each other. The punching operation is thus possible by combining holes having a plurality of various pitches.